Of Operation 2

Glossary

275 HART
Communicator
A handheld master device that uses the HART communication protocol and DDL to configure or communicate with any HART smart device

Bell 202
A U.S. telephone standard that uses 1,200 Hz and 2,200 Hz as 1 and 0, respectively, at 1,200 baud; a full duplex communication standard using a different pair of frequencies for its reverse channel; HART uses Bell 202 signals but is a half-duplex system, so the reverse channel frequencies are not used

Burst (Broadcast) Mode
A HART communication mode in which a master device instructs a slave device to continuously broadcast a standard HART reply message
(e.g., value of a process variable) until the master instructs it to stop bursting

Cable Capacitance Per Unit of Length
The capacitance from one conductor to all other conductors (including the shield if present) in the network; measured in feet or meters

Cable Resistance Per Unit of Length
The resistance for a single wire; meausred in feet or meters

Closed-Loop Control A system in which no operator intervention is necessary for process control

Communication Rate
The rate at which data are sent from a slave device to a master device; usually expressed in data updates per second